In reply to mwr72: I'd think i'd be cheaper to buy one than make. If you're fat/obese you can pick a good down jacket for dirt cheap. Failing that, outdoor shop have the Mountain equipment odion jacket? for £97 atm

dont bother. down is hard to work with and the other fabrics are hard to get in small quantities, plus the demands in cutting and panelling a 3d design (unlike a single layered garment). hoods, pockets and zips are a world of woe.

synthetic is much easier, but still has many of the same issues with design and fabrics.

In reply to mwr72: Synthetic fill has it's pluses and minuses, but if you use it it wont be a down jacket!

I got a MH down one on ebay for £25 with a broken zip a while back, I was going to mend the zip but to be honest I just put a safety pin above the missing teeth and use it as a 1/4 zip over the head, which is fine for me.

I'm sure it's possible to make one but it would be a lot of effort and cost more than buying a decent second hand one. You can sometimes pick up (supposedly) rab down off ebay.

You could possibly turn a synthetic jacket into a half and half by adding down on the inner side and sewing in baffles to keep it all together. A labour of love though and you're not going to save any money DIYing it.

In reply to mwr72: What do you want it for? How warm was your old one? Like ice says, the Uniqlo ones are very good for the money but they are more like super compact/light summer insulation or alternatively best used under a shell. A medium with no hood under a large with hood might work pretty well though and would still only be about 100 quid.

I have no idea but suspect down is very hard to work with, you need to make the jacket first empty of all insulation, then fill it. Down jackets are very "3D", you have to think of them in cross section, then you understand the difference between box wall and stitch through construction. I talked about it in this review http://www.ukclimbing.com/gear/review.php?id=1564

Down if looked after last forever, so you may well be able to get second hand deal for much less than making one would cost.

Synthetic fill is fine, but of course then it isn't a down jacket. I think it would be a pig to make because of the complex construction. TK Maxx, Uniqlo and Decathlon are good places to look for cheap synthetic and in some cases down jackets, probably cheaper than you can buy the materials for. I often wear a Summit7 (no never heard of them either) hooded synthetic jacket that I got from TK Maxx for £25.

In reply to mwr72:
Making a 'stitch through' down jacket isn't rocket science (but don't try for a box-wall or other baffle style, because that's way harder to design and engineer). It can be as simple as getting a couple of windshirts, sticking one inside the other and sewing them together whilst stuffing the space between them with down. How good the end result will be compared to buying cheap off-the-shelf gear though... I don't know ;-) I looked into this a little while back, and decided that the amount of time and effort required meant that buying something ready made was more economical. YMMV.

You can get complete kits, but only from the states so postage and customs may well make it uneconomical: http://thru-hiker.com/kits/whitney_kit.php possibly you could get the plans alone from them and get materials fdrom this side of the atlantic....

Doubtless there are other sources, but you'll need to search. US forums are possibly the best place to search for more advice... search for magic words like 'myog' (make your own gear) on backpackinglight.com, for example.